Process of exhausting and sealing electrical glowlamps and the like



entree sm'rss ?ATEENT @FWQE.

\ KARE FINCKH, or BERLIN-TEMPELHOF, GERMANY, assrGNoR T0 PATENT-mm!- HAND-GESELLSCHAFT FfiR-ELEKTRISCHE GLUHZJL'MPEN m. B. It, or BERLIN,

GERMANY.

PROCESS OF EXHAUS'IING AND SEALING ELECTRICAL GLOWLAMPS AND THE LIKE.

No Drawing.

.1919, upon the application of R. Le Rossignol relates to an apparatus for exhausting incandescent electric lamps and other kinds of glass vessels by means of a container that x is in communication with the interior of lamps placed within it. The connection between the lamps and the interior of the container is established through a small, short exhaust stem or pipe joined to the lamps or vessels, the free ends of the stems or pipes being sealed by fusion inside the container after the lamps or vessels are exhausted. A

' small quantity of glass of a. lower melting 1 process.

According to the pending patent application of R. Le Rossigriol Serial No. 395028 filed ,July 9, 1920, the sealing of the short stems or plpes may be effected by liquefying the ends of the stems by the application of heat and removing them from the heating zone Whilst they are still in a liquid state.

Specificationof Letters Patent. Patented Mal. 28, Application filed June 24, i

1921. Serial No. 480,189.

I have found that instead of depending upon easily fused glass as the means to be relied upon for sealing the vessels, advantageous results will be obtained by employing as the agent for accelerating and establishing the sealing of the vessels, substances which melt with glass and thus result in an easily fused glass being produced. The most noteworthy of such substances are, perhaps, alkaline salts and lead-oxides. They may be applied in any suitable way, as by being spread on in the form of a paste or of a dry powder, or by being put on in the form of a solution that is subsequently dried.

I claim 1.'In combination with a process of exhausting and sealing electrical glowlamps or the like provided with short exhaust stems or pipes for the exhausting operation, applying to the open end of the exhaust stem a substance which lowers the melting point of the glass.

2. In combination with a process of exhausting and sealing electrical glowlamps or the like provided with short exhaust stems 0r pipes for the exhausting operation, applying alkaline salt to the open end of the exhaust stem for the purpose of lowering its melting point. I p

In testimony whereof I afiix my signature in presence of two witnesses.

KARL FINCKH.

Witnesses:

HELENE VON MIDA, WILLY Winnie. 

